Chen Tai C
Department of Medicine, Section of Endocrinology, Diabetes and Nutrition, Boston University School of Medicine, Boston, MA 02118, USA.
Anticancer Res. 2008 Jul-Aug;28(4A):2015-7.
The active form of vitamin D, 1alpha,25-dihydroxyvitamin D (1alpha,25(OH)2D), inhibits proliferation and induces the differentiation of prostate cells in culture, attenuates tumor growth in animal models, and decreases prostate specific antigen (PSA) levels in prostate cancer patients. The enzymes that are responsible for the activation of vitamin D to 1alpha,25(OH)2D include vitamin D-25-hydroxylase (25-OHase) and 25-hydroxyvitamin D-1alpha-hydroxylase (1alpha-OHase or CYP27BJ) and are present in cultured prostate cells. The demonstration that a differential expression of 1alpha-OHase between noncarcinogenic and carcinogenic prostate cells and the ability of epidermal growth factor (EGF) to up-regulate 1alpha-OHase promoter activity in the noncarcinogenic, not the carcinogenic prostate cells suggested that a dysregulation of 1alpha-OHase in cancer cells may lead to the aberrant growth of prostate cancer cells. Thus, the 1alpha-OHase gene is a tumor suppressor gene responsible for the normal regulation of prostate cell growth.
维生素D的活性形式，即1α，25 - 二羟基维生素D（1α，25(OH)₂D），在体外培养中可抑制前列腺细胞增殖并诱导其分化，在动物模型中可减缓肿瘤生长，还能降低前列腺癌患者的前列腺特异性抗原（PSA）水平。负责将维生素D转化为1α，25(OH)₂D的酶包括维生素D - 25 - 羟化酶（25 - OHase）和25 - 羟基维生素D - 1α - 羟化酶（1α - OHase或CYP27BJ），它们存在于培养的前列腺细胞中。非致癌性和致癌性前列腺细胞之间1α - OHase的差异表达，以及表皮生长因子（EGF）能够上调非致癌性而非致癌性前列腺细胞中1α - OHase启动子活性，这表明癌细胞中1α - OHase的失调可能导致前列腺癌细胞的异常生长。因此，1α - OHase基因是一种肿瘤抑制基因，负责前列腺细胞生长的正常调节。
